adding pump delay

Does someone make a freestanding pump delay that will continue to run the boiler pump for a minute or so until the heat is all out of the boiler?Our boiler pump is wired directly to the boiler circuitry and is set to run whenever a zone call for heat through a Taco SR504. The Taco controller trips the R1/W1 on the boiler and causes the boiler to turn on and also run the boiler pump. When the call for heat stops, the pump immediately shuts off and the pipes start banging from overheating. Is there some type of module I can install that will allow the pump to run for a slightly longer time to dissipate the heat?